diff --git a/flang/lib/Lower/IntrinsicCall.cpp b/flang/lib/Lower/IntrinsicCall.cpp
--- a/flang/lib/Lower/IntrinsicCall.cpp
+++ b/flang/lib/Lower/IntrinsicCall.cpp
@@ -485,6 +485,7 @@
   fir::ExtendedValue genIchar(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
   mlir::Value genIeor(mlir::Type, llvm::ArrayRef<mlir::Value>);
   fir::ExtendedValue genIndex(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
+  mlir::Value genIor(mlir::Type, llvm::ArrayRef<mlir::Value>);
   mlir::Value genIshft(mlir::Type, llvm::ArrayRef<mlir::Value>);
   mlir::Value genIshftc(mlir::Type, llvm::ArrayRef<mlir::Value>);
   fir::ExtendedValue genLbound(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
@@ -730,6 +731,7 @@
        {"substring", asAddr},
        {"back", asValue, handleDynamicOptional},
        {"kind", asValue}}}},
+    {"ior", &I::genIor},
     {"ishft", &I::genIshft},
     {"ishftc", &I::genIshftc},
     {"len",
@@ -2500,6 +2502,13 @@
   return readAndAddCleanUp(mutBox, resultType, "INDEX");
 }
 
+// IOR
+mlir::Value IntrinsicLibrary::genIor(mlir::Type resultType,
+                                     llvm::ArrayRef<mlir::Value> args) {
+  assert(args.size() == 2);
+  return builder.create<mlir::arith::OrIOp>(loc, args[0], args[1]);
+}
+
 // ISHFT
 mlir::Value IntrinsicLibrary::genIshft(mlir::Type resultType,
                                        llvm::ArrayRef<mlir::Value> args) {
diff --git a/flang/test/Lower/Intrinsics/ior.f90 b/flang/test/Lower/Intrinsics/ior.f90
new file mode 100644
--- /dev/null
+++ b/flang/test/Lower/Intrinsics/ior.f90
@@ -0,0 +1,9 @@
+! RUN: bbc -emit-fir %s -o - | FileCheck %s
+
+! CHECK-LABEL: ior_test
+subroutine ior_test(a, b)
+  integer :: a, b
+  print *, ior(a, b)
+  ! CHECK: %{{[0-9]+}} = arith.ori %{{[0-9]+}}, %{{[0-9]+}} : i{{(8|16|32|64|128)}}
+end subroutine ior_test
+